Well strainer



| A. LAYNE April 2 5, 1939.

WELL STRAINER Filed May 9, 1956 ESLII E LAYNE. 90mm 5.0M;

L VENTOR ATTORNEY-$- Patented Apr. 1939 UNITED STATES PATENT OFFICE wmsrasmsa Leslie A. Layne, Houston, Tex. Application May's. 1m, Serial No. 78,772

' 3 Claims. (on. ice-s) .The invention relates to an improvement in a combination screen and wall scraper which is adapted to scrape the face of the producing formation so as to open it up to obtain a maximum production,

It will be understood that in the drilling of wells by the rotary method heavy mud or slush is circulated through the drill stem and upwardly through the well bore to carry away the cuttings from the bit and to prevent caving of the formation. When a producing formation is encountered it is usually of a porous nature and it is not uncommon for a cake'of mud to form on the face of the formation which interferes with the how ofthe fluid to be produced from the formation thru the well bore after the mud has been removed. It is desirable therefore to scrape the face of the formation as the mud is being removed so that there will beno interference with the flow of fluid into the well bore from the producing formation.-

The present invention embodies scraper members which are shown as having been attached to the strainer or screen which is positioned in the well bore so that the strainer may be rotated to scrape the formation as it is washed in order to remove any foreign matter which has accumulated on the face of the formation.

One of the objects of the invention is to provide a combination strainer and scraper for well bores.

Another object of the invention is to provide scraping members on the periphery of the strainerscreen so that rotation of the screen as it is lowered into position will scrape the face of the producing formation.to open it up for a maximum flow. Another and further object of the invention will be readily apparent when the following description is considered in connection with the accompanying drawing, wherein:

Fig. 1 is a side elevation of the device positioned in the well bore.

Fig. 2 is a side elevation of; the upper portion.

of the device shown in Fig.1 illustrating the combination of the scraper and the packer.

Fig. 3 is a fragmentary section taken on the line 3-3 of Fig. 1. g

A general practice in completing a well. is to drill the well and set the casing at an elevation above the producing formation and to thereafter drill a well bore such as ,2 into the producing formation illustrated generally at l. I

The strainer and packer assembly is lowered into the well bore to be positioned to the bore 2,

and this assembly is usually "manipulated by a string .of pipe I which may be a string of tubing or a special string of setting pipe known as the .ing the shoe 6 to the lower end of the strainer pipe 1. The strainer is made up in any desired manner to provide a strainer area 8 whereby the fluid being produced may flow into the pipe'and to the surface. The upper end of the strainer carries a coupling 9 to which the liner I2 is afflxed. Both the liner and the screen may be of any desired length, depending upon the location and extent of the producing formation. In some instances the liner may project further up into the well casing.

In order to form a seal with the well bore or casing to prevent the inflow of foreign material, a packer I is usually, provided. This may be of any type or configuration which may be expanded in order to form a seal. This packer is usually secured by a setting tool It which is manipulated by the setting string 4.

with the parts assembled as just described, the entire assembly is lowered into the well bore until the strainer approaches the producing formation 3.

As previously stated, the producing formation 3 may have had formed on the face thereof a thin cake of mud because of the fact that there has been a mud pressure against the formation durthe drilling operation, and water may have been forced back into the producing formation, leaving the cake of mudon the face thereof, and it is desirable to remove this cakeso as to present a clean formation.

As seen in Fig. 1 the strainer 1 is of particular construction in that it is made up of the support pipe l8 which may be provided with a plurality of openings I! through which the fluid being pro- It so as to form a strainer opening of the desired "gauge, depending upon the fineness of the sand in the producing formation 3. The structure of the strainer is one generally used but it has been changed somewhat for the purpose of this invention by affixing to the surface of the strainer wire l9 and the support pipe It a plurality of scraper members 20.

tion with one'base of the triangle, such as 2|, being affixed to the surface 22 of the strainer wire I. Another face 23 of the member pro- As seen in Fig. 3 each of these. members is substantially triangular in cross sec-- jects radially from the pipe so as to present a scraping face in the direction of rotation.

The outside corner of the member projects farthest from the pipe and provides a sharp scraping edge. The inclined face 25 slopes away from the scraping edge and is on the back side when the device is in operation.

Any desired number of these scraper members may be attached, and as seen in Figure 1, they have been carried beyond the upper and lower ends of the strainer wire and curved at 26 so that the end 21 may be aflixed to the scraper blades will be slightly greater than the diameter of the bit that drilled the hole 2. In this manner asthe scraper is lowered into the .hole 2 it may be rotated as it is lowered or it may be lowered and thereafter rotated in order to scrape the face of the formation 3 to remove any adhering matter.

When the screen is being located it is desirable to wash the mud from the well and it is the usual practice to circulate water downwardly through the pipe I and cut through the lower end of the shoe 6 so that it will flow upwardly past the screen and packer and into the casing. In some instances a wash pipe is provided inside of the packer and strainer which engages in the set shoe 6 and serves a conduit to convey the water through the screen. In some instances the screen may be filled with water to prevent the inflow of mud; regardless of how the screen is set it may be rotated to scrape the face of the formation during the washing operation so that the washing feature will carry away the scrapings and they will not be lodged in the well. r

After the screen has been set at the desired elevation the packer l5 may be set by the manipulation of a setting tool l6 so as to anchor may be cleaned as the last'operation before they setting of the packer and after the mud has been washed from the well.-

What is claimed is: 1. A device of the characterdescribed comprising a perforated pipe, a wire wrapped strainer thereon, guard members for said strainer consisting of longitudinal bars fixed to the outer surface of the wrapped strainer, and a scraping edge on said bars to' contact the wall of the formation as said strainer is set whereby to clean the face of the formation as said pipe is rotated. I I

2. A device of the character described comprising a foraminated pipe, a wire wrapped strainer thereon, guard members for said strainer 'consisting of longitudinal bars fixed to the outer surface of the wrapped strainer, and a. scraping edge on said bars to contact the wall of the formation as said strainer is set whereby to clean the face of the formation as said" pipe is rotated, each of said bars being substantially triangular with one side fixed to the strainer.

3. The combination of a strainer pipe having openings therethru, a strainer wire wrapped about said pipe in closely spaced relation to provide a strainer slot about the pipe, the spacing of said wire determining the size 'of material which may not pass, the ends of said wire being anchored to said pipe, and a plurality of scraper members longitudinally attached on I said pipe and overlying said strainer wire.

LESLIE A. LAYNE. 

